FDA rescinds emergency use authorization for hydroxychloroquine, chloroquine for COVID-19 treatment

The U.S. Food and Drug Administration (FDA) rescinded its emergency use authorization of hydroxychloroquine and chloroquine to treat COVID-19 patients.

Based on FDA’s continued review of the scientific evidence available for hydroxychloroquine sulfate (HCQ) and chloroquine phosphate (CQ) to treat COVID-19, FDA has determined that the statutory criteria for EUA as outlined in Section 564(c)(2) of the Food, Drug, and Cosmetic Act are no longer met," the FDA wrote in a June 15 update. "Specifically, FDA has determined that CQ and HCQ are unlikely to be effective in treating COVID-19 for the authorized uses in the EUA."

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"Additionally, in light of ongoing serious cardiac adverse events and other serious side effects, the known and potential benefits of CQ and HCQ no longer outweigh the known and potential risks for the authorized use. This warrants revocation of the EUA for HCQ and CQ for the treatment of COVID-19," the FDA said.

The move means that shipments of the drugs obtained by the federal government will no longer be distributed to state and local health authorities. The drugs are still available for alternate uses, so U.S. doctors could still prescribe them for COVID-19 — a practice known as off-label prescribing.

In previous months, hydroxycholoroquine and chloroquine had been previously touted by President Donald Trump as effective measures for treating the novel coronavirus, with the president himself indicating in May that he was taking hydroxychloroquine to ward off COVID-19 symptoms.

However, the actual efficacy of the drugs has been in question. In June, the World Health Organization resumed a study on hydroxychloroquine that had been paused "because of concerns raised about the safety of the drug." 

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Also in June, The Lancet retracted a study on the drugs. According to the background from that study, "although generally safe when used for approved indications such as autoimmune disease or malaria, the safety and benefit of these treatment regimens are poorly evaluated in COVID-19."

In April, the FDA had previously advised against using the drugs to treat COVID-19 outside of a hospital or clinical trial setting, due the risk of heart rhythm problems.

Remdesivir, an experimental COVID-19 treatment previously used to treat Ebola patients, has also garnered massive attention as the world scrambles to contain the pandemic with a proven medicine or preventative vaccine. 

As of June 15, there are eight COVID vaccine candidates in Phase II trials and two that are in Phase III, according to The New York Times. Health officials cautioned in past months that a COVID-19 vaccine is still projected to be around 12-18 months away.

The Associated Press contributed to this story.